Search

Objective: Assess whether horizontal ridge augmentation with guided bone regeneration (GBR) using deproteinized bovine bone mineral (DBBM), autologous bone, and a resorbable collagen membrane supports successful implant placement., Materials and Methods: This open, prospective, single-cohort, multicenter clinical study included patients with ridge defects that required GBR prior to implant insertion. The primary endpoint was radiologically assessed bone gain after 8 months post-GBR, measured at the center of planned implant sites. Secondary endpoints included implant survival and success, marginal bone levels (MBLs), MBL changes, and soft tissue health., Results: Of 45 patients evaluated 8 months post-GBR, nine experienced dehiscence in the first 3 weeks of the healing period. GBR led to radiologically determined mean bone width gain of 4.0 ± 1.5 mm and 4.8 ± 1.7 mm, measured 1 and 3 mm from the top of the crest, respectively, allowing successful implant placement in 44 patients (97.8%). The cumulative implant survival and success rates were 98.9% and 95.5%, respectively. MBLs were stable: -1.18 ± 0.64 mm at definitive prosthesis placement (DPP) and - 1.07 ± 0.74 mm at 1 year. Soft tissue health and esthetics (plaque and bleeding indices, papilla, keratinized mucosa, and pink esthetic score) improved from DPP to 1 year. Patients were highly satisfied with implant function and esthetics, and their oral health-related quality of life improved., Conclusions: GBR using DBBM and a collagen membrane offered a safe and effective treatment option for horizontal ridge augmentation sufficient to support implant-based tooth rehabilitation., Trial Registration: Registered at ClinicalTrials.gov NCT03028922 (registrations sites, as above listed affiliations, first posted January 23, 2017)., (© 2024 The Author(s). Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

The aim of this study is to evaluate the anatomical characteristics of the posterior region of the mandible and their surgical relevance related to bone harvesting procedures. Fifty retromolar cone beam computed tomography scans were analyzed considering the donor site anatomies. For each site, linear measurements were taken of cross-sectional scans to record perpendicular distances between the mandibular canal (MC) and the vestibular and crestal bone walls. Data showed that the distance from the MC to the vestibular bone wall is lower in the ramus area than in the external oblique ridge area (< 2.00 mm in 26% of cases). However, the distance between the MC and the crestal bone wall is higher in the ramus area than in the external oblique ridge area. There is less bone thickness in the ramus area, and this could expose the inferior alveolar nerve to damage if osteotomies are performed with fewer depth limitations, as reported in the literature.

Autogenous bone harvesting is a well-documented surgical procedure. Autogenous mandibular bone harvesting carries a risk of anatomical structural damage because the surgeon has no three-dimensional (3D) control of the osteotomy planes. The aim of this case series was to describe the results of mandibular bone block harvesting applying computer-guided surgery. A sample of 13 partially dentate patients presenting bone deficiencies in the horizontal and/or vertical plane were selected for autogenous mandibular bone block graft. The bone block dimension was planned through a computer-aided design (CAD) process, defining ideal bone osteotomy planes to avoid damage to anatomical structures (nerves, teeth roots, etc) and to generate a surgical guide that imposed the 3D working direction to the bone-cutting instrument. The bone block dimension was always related to the defect dimension to be compensated. A total of 13 mandibular bone blocks were harvested to treat 16 alveolar defects (9 vertical and 7 horizontal). The mean planned mesiodistal dimension of the bone block was 24.8 ± 7.3 mm, the mean height was 8 ± 1 mm, and the mean thickness was 4 ± 2 mm. None of the treated patients experienced neurologic alteration of their alveolar nerve function. The preliminary data from this case series suggested that computer-guided bone harvesting could be a concrete opportunity for clinicians to obtain an appropriate volume of autogenous bone in a safe manner.

Objectives: The clinical efficacy of a wearable pulsed electromagnetic field (PEMF) therapy device was assessed in terms of pain and quality of healing after tooth extraction., Study Design: This randomized, parallel design, placebo-controlled study involved 120 patients undergoing unilateral mandibular third molar extraction and assigned to three groups after surgery. Test and placebo patients wore enabled or disabled PEMF devices, respectively, and controls wore no device. Patients recorded pain (on the visual analog scale) and analgesic use for a week, after which healing complications were assessed., Results: Test patients had only slightly lower visual analog scale scores and analgesic use, but significantly fewer cases of dehiscence than placebo patients., Conclusions: PEMF therapy delivered by a wearable device improved soft tissue healing and may be a useful adjunct for pain management after oral surgery., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to investigate the marginal precision of computer numeric control-milled frameworks fabricated of grade 4 commercially pure titanium or cobalt-chrome alloy through digital technology and to compare them with conventional cast frameworks., Material and Methods: A titanium cast of a mandibular arch with six implant analogs was used as a master. The master cast was measured with a coordinate measuring machine. Fifteen rigid anatomic frameworks were created on the master cast in cast gold alloy and milled in titanium or cobalt-chrome material. The fifteen anatomic frameworks were measured in the same manner as the master cast. While the milled frameworks were measured once, at the end of the milling process, the cast anatomic frameworks were measured twice: immediately after the casting and divesting procedures and again after a technical adaptation procedure. Each anatomic framework was weighed. To compare the measurements obtained from each group of frameworks, descriptive statistics were calculated and one-way analysis of variance was performed, with values considered statistically significant at P < .05., Results: The mean weight of the cast frameworks was 33.41 g, the cobalt-chrome frameworks weighed 18.12 g on average, and the titanium frameworks averaged 8.7 g. The mean values for three-dimensional deviation of the center point position for each group of frameworks were 261 μm (cast frameworks before adaptation), 49 μm (cast frameworks after adaptation), 26 μm (milled frameworks in cobalt-chrome), and 26 μm (milled frameworks in titanium)., Conclusions: Within the limitations of this in vitro study, absolute passive fit cannot be achieved, regardless of material and fabrication technique. Anatomic milled frameworks fabricated in titanium or cobalt-chrome presented reduced center point deviation compared to cast frameworks. Titanium frameworks weighed less than cobalt-chrome and cast gold alloy frameworks.

Background: The composition of the fully healed edentulous ridge of the posterior maxilla was recently examined and was found to contain about 50% mineralized bone and 16% bone marrow., Aim: The objective was to examine the composition of the tissue of the fully healed ridge in different portions of the maxilla and the mandible in partially dentate subjects., Material and Methods: Eighty-seven healthy subjects were included. A trephine drill was used to harvest hard tissue specimens. The biopsies were decalcified, embedded in paraffin, sectioned, stained, and examined using a point-counting procedure., Results: The marginal portion of the jaws almost consistently contained a cortical cap that was significantly wider in the mandible than in the maxilla and twice as wide in the anterior as in the posterior segments of the mandible. Lamellar bone and bone marrow were the dominating tissue elements. Lamellar bone occupied about 63% of the tissue in the mandible and 46% in the maxilla. The maxilla contained about 23% bone marrow as compared to 16% in the mandible. In the mandible, 70% (anterior) and 57% (posterior) were made up of lamellar bone. In the maxilla, the proportion of lamellar bone in the anterior and posterior segments was similar (about 45%). Bone marrow occupied close to 40% of the anterior maxilla, while in the posterior maxilla and the anterior and posterior mandible marrow comprised between 13 and 18%., Conclusion: Marked differences existed with respect to tissue composition of the edentulous ridge between the maxilla and the mandible. The cortical crest was wider in the mandible than in the maxilla, and widest in the symphysis region of the mandible. The proportion of bone marrow was greater in the maxilla than in the mandible. The maxillary front tooth region was poor in lamellar bone but rich in bone marrow, while the anterior mandible contained large amounts of mineralized bone but small amounts of bone marrow., (© 2012 John Wiley & Sons A/S.)

Aim: To evaluate the influence of implant positioning into extraction sockets on bone formation at buccal alveolar dehiscence defects., Material and Methods: In six Labrador dogs the pulp tissue of the mesial roots of (4) P(4) was removed and the root canals were filled. Flaps were elevated bilaterally, the premolars hemi-sectioned and the distal roots removed. The implants were placed in contact with either the buccal (test site) or with the lingual (control site) bony wall of the extraction sockets. Healing abutments were affixed and triangular buccal bony dehiscence defects, about 2.7 mm deep and 3.5 mm wide, were then prepared. No regenerative procedures were done and a non-submerged healing was allowed. After 4 months of healing, block sections of the implant sites were obtained for histological processing and peri-implant tissue assessment., Results: After 4 months of healing, the bony crest and the coronal border of osseointegration at the test sites were located 1.71 ± 1.20 and 2.50 ± 1.21 mm apically to the implant shoulder, respectively. At the control sites, the corresponding values were 0.68 ± 0.63 and 1.69 ± 0.99 mm, respectively. The differences between test and control reached statistical significance (P < 0.05). Residual marginal bone defects were found both at the test and control sites. A statistically significant difference between test and control sites was only found at the lingual aspects (depth 2.09 ± 1.01 and 1.01 ± 0.48 mm, respectively). Similar heights of the buccal biological width were observed at both sites (about 5.1 mm)., Conclusions: The placement of implants in a lingual position of the extraction sockets allowed a higher degree of bone formation at buccal alveolar dehiscence defects compared with a buccal positioning., (© 2012 John Wiley & Sons A/S.)

Objective: The aim of this study was to assess the influence of inclination of the object on the reliability and reproducibility of linear measurements of anatomic structures of the mandible on images obtained using cone-beam CT (CBCT)., Methods: Ten linear dimensions between anatomical landmarks were measured in a dry mandible. The measurements were performed with a manual calliper three times by three observers. The mandible was scanned with Planmeca Promax 3D cone-beam CT (Planmeca Oy, Helsinki, Finland) with the base of the mandible parallel as well as tilted 45° to the horizontal plane. Computer measurements of the linear dimension were performed by three observers. The radiographic measurements were performed four times for each experimental setting. A total of 240 measurements were performed. Reproducibility was evaluated through comparison of standard deviation (SD) and estimation of intraclass correlation coefficient (ICC). The error was estimated as the absolute difference between the radiographic measurements and the mean manual calliper measurements., Results: The mean SD for the radiographic measurements was 0.36 mm for the horizontally positioned mandible and 0.48 mm for the inclined mandible. The ICC between examiners was 0.996 mm, between sessions was 0.990 mm and between CBCT measurements and calliper was 0.992 mm. The overall absolute mean measurement error was 0.40 mm (SD 0.39 mm). The percentage of errors that exceeded 1 mm was 6.7%., Conclusion: The results revealed high reliability of measurements performed on CBCT images independently from object position, examiner's experience and high reproducibility in repeated measurements settings.